This invention relates to a sealing element made of water-resistant elastomers or plastomers for outer corners on flat roofs and engineering constructions.
When sealing flat roofs and engineering constructions by means of plastics sheets, the sealing of corners against water (whether under pressure or not) causes serious problems. This is the case when sealing outer corners where two surfaces, which meet at an angle and are often mutually perpendicular, extend into an almost horizontal surface, as in the case of a structural part being brought through a flat roof, e.g. a chimney; and also when sealing inner corners, where two mutually perpendicular surfaces meeting at an angle enclose a horizontal surface as a boundary. In order to simplify the construction work, specially shaped sealing elements made of weather-resistant, resilient plastics materials which match the corners in question are used, the sealing elements being welded or stuck to the edges of the laid plastics sheets adjoining the corner areas.
Known shaped sealing elements of this kind (see for example German Utility Model No. 70 42 051) are generally manufactured from plane cuts of a corresponding plastics sheet using the cupping process. When forming outer corners, these cuts must be greatly stretched in the area enclosing the projecting edge of the corner. The sealing element is therefore subject to the greatest extension along the line where it will abut the outer edge of the projecting corner. However, during construction of the roof, the shaped sealing element is most liable to damage on this edge. In addition the stretching in this edge area increases with increasing distance from the corner point of the shaped part, by virtue of which the known sealing elements for outer corners are limited in their total overall size. Similarly, if the thickness of the material exceeds a certain size there is the danger that the sealing element will tear from the border at the edge enclosing the outer corner.